/**
 * This file is part of 1genia trampoline
 * Copyright (C) 2007 1genia (contact@1genia.com)
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; version 3 of the License. 
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details. 
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; see the file COPYING.TXT.  If not,
 * write to the Free Software Foundation, Inc., 51 Franklin Street,
 * Fifth Floor, Boston, MA 02110-1301, USA. 
 **/
/**
 * 
 */
package com.genia.toolbox.persistence.memory.criteria.field;

import java.util.List;

import com.genia.toolbox.persistence.basis.criteria.BasicCriteriaResult;

/**
 * TRhis field represent the count of an aggregate.
 */
public class CountAggregateOperationField
    extends AbstractMemoryField
{

  /**
   * Return the value of this field for the given line of result.
   * 
   * @param lines
   *          the line of result we compute the field on
   * @return the value of this field for the given line of result
   */
  @Override
  public Double getValue(final List<BasicCriteriaResult<?>> lines)
  {
    return new Double(lines.size());
  }



  /**
   * returns if this <code>Field</code> is an aggregate.
   * 
   * @return <code>true</code> if this <code>Field</code> is an aggregate,
   *         <code>false</code> otherwise.
   */
  public boolean isAggregate()
  {
    return true;
  }

}
